Statement of the Technical Field
The present invention relates to the field of policy based differentiation and more particularly to the real-time monitoring of the enforcement of the terms of a service level agreement (SLA).
Description of the Related Art
The modern global network can be viewed as a complex interweaving of multiple network technologies, server platforms, client capabilities and application requirements. The vast majority of network technologies handle device requests indiscriminately. That is, regardless of the identity of the requester or the type of request, each device request can be processed with equal priority. Given the exponential increase in network traffic across the Internet, however, more recent network-oriented computing devices have begun to provide varying levels of computing services based upon what has been referred to as a “policy based service differentiation model”.
In a policy based service differentiation model, the computing devices can offer many levels of service where different requests for different content or services which originate from different requestors receive different levels of treatment depending upon administratively defined policies. In this regard, a service level agreement (SLA) can specify a guaranteed level of responsiveness based upon a pre-defined policy. More particularly, the SLA is a contract that specifies an agreement between a service provider and customer regarding a level of service to be provided by the service provider to the customer in respect to a specific resource.
The policy based service differentiation model is the logical result of several factors. Firstly, the number and variety of computing applications which generate requests across networks both private and public has increased dramatically in the last decade. Each of these applications, however, has different service requirements. Secondly, technologies and protocols that enable the provision of different services having different levels of security and quality of service (QoS) have become widely available. Yet, access to these different specific services must be regulated because these specific services can consume important computing resources such as network bandwidth, memory and processing cycles. Finally, business objectives or organizational goals can be best served when discriminating between different requests rather than treating all requests for computer processing in a like manner.
Within the modern enterprise, the enterprise can receive a substantial benefit for effectively providing differentiated service to different customers and different data so that some customers and data receive a higher level of service than other customers and data on the network. That is to say, where the enterprise satisfies the expected service level of a valued customer, the enterprise can retain the customer. Conversely, where the enterprise fails to satisfy the expected level of service of a valued customer, the enterprise likely can lose the customer. Hence, differentiated service can be an important component of e-commerce inasmuch as a customer always can be viewed as merely “one click away” from a competitor's system where response times falter.
Accordingly, the enforcement of the terms of an SLA can be of paramount importance in managing the customer service relationship. To that end, service level management systems have become commonplace in the enterprise. A service level management system can track services provided to customers and compare the delivery of services to the service terms of a corresponding SLA. Performance metrics can be collected over time in respect to the resources associated with the SLA and the metrics can be evaluated to determine if any of the terms of the SLA have been violated.
The evaluation of performance metrics can be performed in the context both of a historical timeframe where the SLA compliance is determined after the fact, and also in real-time responsive to the occurrence of events in the monitored system. In the case of real-time evaluation, the performance metrics can be used to determine the impact of the event upon the terms of the SLA immediately after the occurrence of the event. Traditionally, service level management systems process real-time events at the individual resource level forming a part of the service to determine if the SLA with respect to the service has been impacted in the immediate sense, or whether the SLA will be impacted in the future. Still, there are many other factors within the enterprise that can cause an immediate or future impact on the satisfaction of the terms of an SLA, but in a more indirect manner that would not be exposed through just individual resources associated with an SLA.